JP2017528182A - A series of absorbent articles having channel forming areas - Google Patents

Abstract

A series of absorbent articles, particularly infant care articles, comprising at least two, preferably at least three, absorbent articles of various sizes, comprising a wearer facing side, a garment facing side, and an absorbent core (28). The absorbent core (28) comprises an absorbent material (80) between the wearer facing side and the garment facing side. Each absorbent article is conceptually divided by a longitudinal axis (80) and has a front region (36), a rear region (38), and an intermediate crotch region (37). The absorbent core includes a pair of channel forming areas (26) that are at least partially present in the crotch region of the article. The channel forming areas are symmetrically arranged on both sides of the longitudinal axis and are concave toward the longitudinal axis. Each channel forming area has a length (CL) and a height (CH), and the ratio of the channel forming area length to height (CL / CH) increases with the size of a series of articles. .

Description

  The present invention relates to an absorbent article for personal hygiene of the type used by individuals with incontinence to absorb bodily excretion, particularly in urine. These articles include, among other things, diapers for infants and children (including training pants), sanitary pads for women, and adult incontinence articles.

  These absorbent articles for personal hygiene typically comprise an absorbent material disposed between a liquid permeable skin facing sheet (top sheet) and a liquid impermeable clothing facing sheet (back sheet). . Superabsorbent polymer (“SAP”) materials that are capable of absorbing urine several times their weight are now commonly used as absorbent materials. SAP particles are usually mixed with cellulose fluff, but cellulose-free absorbent cores (so-called “airfelt-free” absorbent cores) have been commercialized more recently. The absorbent material may typically be encapsulated within a separate component called the absorbent core, but more simply can also be disposed directly between the topsheet and the backsheet.

  Absorbent articles for personal hygiene are usually offered in various sizes to accommodate the specific needs of various wearers. For example, baby care diapers are usually segmented according to the weight of the wearer, with each diaper size corresponding to a range of infant weights. The size of each article increases with the weight range. The number of sizes offered and the corresponding weight ranges can vary between manufacturers and markets. Similar segmentations exist for other categories of personal hygiene articles, such as feminine care and adult incontinence articles, and can be related to the severity of incontinence as well as the size of the wearer.

  Usually, the size of the absorbent core and the amount of absorbent material increase with the size of the article, especially to accommodate more urine as long as the wearer is still incontinent. However, older children's articles (eg, training pants) in a training phase that are beginning to emit less may have a smaller amount of absorbent material as compared to products for younger children. However, the overall design and ratio of the absorbent core generally does not vary greatly with product size.

  Recently, providing an absorbent structure comprising a superabsorbent polymer, an optional cellulosic material, and at least a pair of substantially longitudinal absorbent material-free zones that can form channels. Has been proposed. Examples of such structures are described in WO 2012/170778 (see also Rosati et al., WO 2012/1707779, WO 2012/170781 and WO 2012/170808), It is disclosed in Publication No. 2014/093319, International Publication No. 2104/093311 (both Arizti) and International Publication No. 2014/093310 (Ehrnsperger). The material absence zone in these disclosures may be curved. Other prior art discloses channels that are straight, such as those in WO 95/11652 (Tazer) or WO 2012 / 052172A1 (Van Malderen). Oriented in the longitudinal and / or transverse direction of the core.

  WO 2008/023291 (Cohen) discloses that children at various stages of development have different dominant positions. Cohen addresses the different dominant leg positions of newborns, infants, and children by providing a series of disposable articles with various leg opening positions. However, Cohen does not disclose adapting the structure of the absorbent core according to the stage of wearer development.

International Publication No. 2012/170778 International Publication No. 2012/1707779 International Publication No. 2012/170781 International Publication No. 2012/170808 International Publication No. 2014/093319 International Publication No. 2104/093311 International Publication No. 2014/093310 International Publication No. 95/11652 International Publication No. 2012 / 052172A1 International Publication No. 2008/023291

  There is a permanent need to improve the fit and comfort of absorbent articles. In order to provide adequate coverage and capacity, it is known to provide absorbent articles of various dimensions (in the longitudinal and lateral directions) based on the infant's weight. The inventors have now found that the dimensions of the channel forming area should be specifically adapted to the size of the wearer. Adapting the dimensions, especially the curvature of the channel-forming area, to the infant's morphological changes (height, weight and leg circumference) to allow a proper fit for all diaper ages It is beneficial to. In addition, the inventors have shown a correlation between channel dimensions and infant morphology parameters (ie leg circumference, etc.) that can be used to optimize the fit for a given size. discovered. In short, the geometry of the channel forming area should be adapted to the size of the wearer in order to provide a better fit.

  The present invention relates to a series of absorbent articles comprising at least two absorbent articles of various sizes. Each article has a wearer facing side, a garment facing side, and an absorbent core between the wearer facing side and the garment facing side. Each absorbent article further includes a longitudinal axis, a front region, a rear region, and a crotch region. The absorbent core includes a pair of channel forming areas that are at least partially present in the crotch region of the article, the channel forming areas being symmetrically disposed on opposite sides of the longitudinal axis and on the longitudinal axis. It is concave toward each other, and each channel forming area has a certain length (CL) and a certain height (CH). The ratio between the length and height of the channel forming area (CL / CH) increases with the size of the article to provide an improved fit.

FIG. 3 shows a plan view of an exemplary absorbent article in the form of a taped diaper with an inner layer partially exposed and an absorbent core having a pair of curved channel forming areas. FIG. 2 shows a plan view of the absorbent core of FIG. 1 separated. 3 shows a cross section of the core of FIG. 3c shows the same cross-section of the core of FIG. 3a after the core has absorbed fluid and swelled. An enlarged section of the central part of one channel forming area is shown. Fig. 3 schematically illustrates various absorbent cores having various channel forming areas that can be used to make a series of articles according to the present invention. Fig. 3 schematically illustrates various absorbent cores having various channel forming areas that can be used to make a series of articles according to the present invention. Fig. 3 schematically illustrates various absorbent cores having various channel forming areas that can be used to make a series of articles according to the present invention. Similar to FIGS. 5a, b, c, but with a separate channel formation area. Similar to FIGS. 5a, b, c, but with a separate channel formation area. Similar to FIGS. 5a, b, c, but with a separate channel formation area. Fig. 5 shows a core having a channel-forming area shaped differently. Fig. 5 shows a core having a channel-forming area shaped differently. It is a chart which shows the relationship between a swelling and leg circumference (mm unit) as a function of body weight (kg unit).

Overview of Absorbent Article An exemplary absorbent article according to the present invention in the form of an infant taped diaper 20 is shown in FIG. FIG. 1 is a plan view of an exemplary diaper 20 in a flattened state, with a portion of the structure cut away to better illustrate the structure of the diaper 20. Diaper 20 is shown for illustrative purposes only. The absorbent article can also be, for example, a pants-type article having a preformed side seam. Unless otherwise noted, the dimensions and regions disclosed herein apply to this flattened form article. When a particular part of an article is tensioned by a stretchable element, the article is generally flattened using a clamp and / or an adhesive surface along the outer periphery of the article Therefore, the top sheet and the back sheet can be pulled with a pin. Closed articles such as training pants can be cut along the side seams so that they can be applied to a flat surface.

  The absorbent article 20 has a front edge 10, a rear edge 12, and two longitudinally extending side (lateral) edges 13, 14 that connect the front edge and the rear edge. . The leading edge 10 is the edge of the article intended to be placed towards the front of the user when worn, and the trailing edge 12 is the opposite edge. 1, when viewed from the wearer's side in a flat, unfolded configuration, the absorbent article is conceptually divided by a longitudinal axis 80, which is the front of the article. It extends from the edge to the trailing edge and divides the article into two substantially symmetrical halves about this axis. This axis 80 may generally coincide with the longitudinal axis 80 'of the absorbent core. The article has a length L measured along axis 80 from the trailing edge to the leading edge. The absorbent article 20 can also be conceptually divided by the transverse axis 90 into front and rear areas of equal length as measured on the longitudinal axis when the article is in such a flat state. The transverse axis 90 of this article is perpendicular to the longitudinal axis 80 and is located at half the length of the article. The intersection of the longitudinal axis and the transverse axis is referred to herein as the crotch point “C”.

  The absorbent article is further conceptually divided into a front region 36, a rear region 38, and a crotch region 37 therebetween. The front region 36 is defined as a region extending from the front edge 10 of the article and having a length of one third of L along the longitudinal axis 80. The rear region 38 is defined as a region extending from the rear edge 12 of the article and having a length of one third of L along the longitudinal axis 80. The crotch region 37 is an intermediate region that is between the front region and the rear region, and similarly has a length of one third of L along the longitudinal axis 80.

  The absorbent article 20 includes a wearer-facing side that can be formed mainly by a liquid-permeable topsheet 24, a garment-facing surface that can be formed by a liquid-impermeable backsheet 25, and between the topsheet 24 and the backsheet 25. The absorbent core 28 is provided. The absorbent core 28 is shown separately in FIG. The topsheet 24, backsheet 25, absorbent core 28, and other article components can be assembled in a variety of well-known configurations, particularly by gluing and / or hot embossing. Exemplary diaper assemblies are described, for example, in U.S. Pat. Nos. 3,860,003, 5,221,274, 5,554,145, 5,569,234, No. 5,580,411, and 6,004,306. The absorbent article is preferably thin with calipers of 2.0 mm to 8.0 mm, especially 3.0 mm to 6.0 mm at the crotch point, as measured, for example, using the absorbent article caliper test described below. Is.

  The absorbent article 20 also includes additional components such as a capture layer and / or distribution layer (collectively referred to as capture-distribution system “ADS”, designated 54), a topsheet 24 and a backsheet 25. An elasticized gasket cuff 32 and an upright barrier leg cuff 34 may be further provided. The ADS can be shaped and / or curved toward the trailing edge of the article, for example as disclosed in WO 2014/093323. FIG. 1 also includes other exemplary tapes, such as a fastening system that includes a fastening tab 42 that is attached toward the trailing edge 12 of the article and cooperates with a landing zone 44 towards the leading edge 10 of the article. The attached diaper component is shown. These fastening mechanisms are typically not present in pant-type articles having preformed side seams. The absorbent article also includes other typical components not shown, such as a rear elastic waist mechanism, a front elastic waist mechanism, a transverse barrier element, a wetness indicator that changes appearance when in contact with urine, and a lotion application. You may prepare. These components are well known in the art and will not be discussed further herein. With reference to WO 2014/093310, some examples of these components are disclosed in more detail.

  Typically, adjacent layers are conventional, such as slot coating on all or part of the surface of the layer, swirling glue, or adhesive coating by spraying, or thermal bonding, or crimping, or combinations thereof. They are joined together using a bonding method. Many of the connections between the components are not shown in the drawings for clarity and readability. Bonds between layers of the article should be considered present unless specifically excluded. Adhesives can typically be used, for example, to improve the adhesion of different layers between the backsheet and the core wrap as disclosed in WO 2012/170341 A1, for example. The adhesive used may be any standard hot melt adhesive known in the art. The absorbent core 28 and channel formation area 26 will now be further described.

Overview of Absorbent Core 28 As used herein, the term “absorbent core” refers to the individual components of an absorbent article comprising an absorbent material encapsulated within a core wrap. Absorbent core as defined herein does not include a capture distribution layer or, if present, does not include a multilayer system. The core wrap is usually formed by one or two layers of nonwoven or tissue material, but for some articles of simple construction, the core wrap may be partially formed by a topsheet and / or a backsheet. May be completely formed. The absorbent core is usually the component of an absorbent article that has the highest absorbent capacity of all the components of the absorbent article and contains all or at least a majority of the superabsorbent polymer (SAP). . The core can consist essentially of a core wrap, an absorbent material, and an optional adhesive. The terms “absorbent core” and “core” are used interchangeably herein.

  The absorbent core of the present invention is substantially planar. Substantially planar means that the absorbent core can be laid flat on a planar surface. The absorbent core is also typically thin and comfortable and can be placed on a curved surface, such as a drum, during its manufacturing process, or stored and continuously as a continuous roll of storage material before being processed into an absorbent article. Can be processed.

  For ease of discussion, the exemplary absorbent cores of FIGS. 2-3 are represented in a flat state. The absorbent core is relatively thin relative to other dimensions in the transverse direction (x) and the longitudinal direction (y). Each of these directions corresponds to the crossing method and the longitudinal direction of the article. Unless otherwise noted, the dimensions and regions disclosed herein apply to this flattened form of the core. The same applies to the absorbent article exemplarily shown in FIG. 1 as a taped diaper incorporating a core. The absorbent cores and articles of the present invention are described with reference to the drawings and reference numerals referenced in those drawings. However, they are not intended to limit the scope of the claims unless otherwise specified.

  The illustrated absorbent article 28 has a leading edge 280, a trailing edge 282, and two longitudinal side edges 284, 286 connecting the leading edge and the trailing edge. The leading edge of the core is the edge of the core that is intended to be placed towards the leading edge of the absorbent article in which the core is or will be incorporated. Typically, the core leading edge 280 and trailing edge 282 are shorter than the core longitudinal side edges 284, 286. The absorbent core also includes an upper side 288 and a lower side 290. The upper side of the core is or is intended to be placed towards the wearer facing side of the article (top sheet 24) and the lower side is the garment facing side of the finished article (back sheet 25). Is the side that is or is intended to be located. The upper side of the core wrap can be more hydrophilic than the lower side, for example after treatment with a wetting agent.

  The absorbent core is parallel to the longitudinal direction y and viewed from the leading edge 280 to the trailing edge 282 when viewed in the plane formed by the longitudinal direction and the transverse direction (x, y). Can be conceptually divided into two substantially symmetric halves by a longitudinal axis 80 'that extends and divides the core. The length L ″ of the core, particularly if it is present along the longitudinal axis 80 ′ from the leading edge 280 to the trailing edge 282, including the area of the core wrap that does not enclose the absorbent material. Measured at the front and back seals. The crotch point C 'of the core is the point that is vertically aligned with the crotch point C of the absorbent article and is typically located on the longitudinal axis 80' of the absorbent core.

  The core width W "is the maximum dimension of the core wrap measured along the transverse direction x, which is perpendicular to y. The outer shape of the absorbent core defined by the core wrap can be generally rectangular. The core width W "and length L" may vary depending on the intended application. The core wrap may also be shaped with a width at the crotch point C 'narrower than the width at the front and / or rear of the core wrap. For example, for infant care applications such as diapers and infant training pants, depending on the size and volume desired, the core width can typically range from 4 cm to 22 cm and the length from 10 cm to 62 cm. The length to width ratio (L "/ W") can range, for example, from 2 to 10. Adult incontinence articles are usually longer and wider than infant articles and may have larger dimensions.

  Absorbency comprises an absorbent material 60 enclosed within a core wrap. The absorbent material may comprise a high proportion of superabsorbent polymer (abbreviated herein as “SAP”). As used herein, a “superabsorbent polymer” is a 0. 0 of at least 10 times their weight as measured using a centrifugal retention capacity (CRC) test (EDANA method WSP 241.2-05E). It refers to an absorbent material that can be a cross-linked polymeric material that can absorb 9% saline. The SAP may specifically have a CRC value of greater than 20 g / g, or greater than 24 g / g, or 20-50 g / g, or 25-40 g / g. The SAP content may represent, for example, at least 80% and up to 100% by weight of the absorbent material contained within the core wrap. SAP can be in particular in particulate form (SAP particles), but other forms are also contemplated, such as absorbent foam or fibers. Further detailed examples of absorbent materials, in particular SAP, are disclosed in WO 2014/093310 (Ehrnsperger). In particular, the absorbent material may comprise SAP particles that require an absorption achievement time (T20) of less than 240 g of 20 g / g as measured according to the K (t) test method described in WO2012174026. Or may consist of it.

  The absorbent material may in particular be substantially free of cellulose fibers, ie at least 20% by weight of cellulose fibers, in particular less than 10% by weight or less than 5% by weight relative to the total weight of the absorbent material. And up to 0% by weight of cellulose fiber. This allows the absorbent core to be relatively thin, in particular thinner than conventional cores containing cellulosic fibers. Specifically, the core thickness (before use) measured at the crotch point (C ′) or any other point on the surface of the core according to the core thickness test described herein is from 0.25 mm to It may be 5.0 mm, specifically 0.5 mm to 4.0 mm.

  The absorbent material 60 forms the absorbent material placement area 8 in the core wrap. The disposition area 8 may comprise a continuous layer of absorbent material in the plane of the core, as shown in FIG. Alternatively, the disposition area may comprise a separate or bonded land area comprising an absorbent material and a non-material junction area between them. The basis weight (the amount deposited per unit surface area) of the absorbent material can also be varied to produce a macroscopic waveform distribution in the longitudinal direction (y) and / or the transverse direction (x). Typically, the absorbent material of the core will advantageously be somewhat less towards the back portion 38 of the core, since higher absorbency is usually required towards the crotch region and the front region. Can be distributed. However, other absorbent material distributions are also conceivable, for example, a uniform distribution throughout the absorbent material area 8 can be made more easily.

  The absorbent material placement area 8 may be generally rectangular as shown in FIG. 2, but a shaped absorbent material placement area is also desirable. A typical shaped placement area is narrow in the crotch region, and the crotch region has at least one point where the width is narrower than the width of the absorbent placement material area in the front and / or back region. In particular, it forms an absorbent material area of a dogbone or hourglass shaped area. Further detailed examples of absorbent material distributions that can be used herein are disclosed in WO 2014/093310 (Ehrnsperger).

  Various absorbent core designs with large amounts of SAP have been proposed in the past. The process used is one that can deposit SAP relatively accurately at a relatively high rate, and this process may be used to make the absorbent core of the present invention, for example, US Pat. 599,335 (Goldman), European Patent 1,447,066 (Busam), International Publication No. 95/11652 (Tanzar), US Patent Publication No. 2008/0312617 (Hundorf), International Publication No. 2012/052172. No. (Van Malderen), especially 2012/170778 (see also Rosati et al., 2012/1707779, 2012/170781, and 2012/170808).

  The absorbent material is deposited using, for example, SAP technology as disclosed in US Patent Publication Nos. 2006/024433 (Blessing), 2008/0312617 and 2012 / 0051166A1 (both Hundorf et al.). May be. This technique uses a transfer device such as a printing roll to deposit SAP particles on a substrate disposed on a lattice-like support (for example, a lion drum). The grid may include a plurality of crossbars extending and spaced substantially parallel to each other to form ribs extending between the crossbars. SAP is attached to the inside of these ribs. This technique is particularly fast and accurate for depositing SAP on a substrate so that an area substantially free of absorbent material is provided, surrounded by the absorbent material, through which core wrap is applied. Can be bonded to itself to form a channel forming area. Areas substantially free of absorbent material can be formed, for example, by providing areas on the support where no SAP is deposited, and then joining both sides of the core wrap together through areas that do not contain these absorbent materials. One way to achieve this is disclosed by way of example in US 2012/0312491 (Jackels).

  The core wrap can be formed of any substrate material suitable for receiving and containing the absorbent material. Typical substrate materials used are inter alia nonwovens, paper, tissue, films, woven fabrics or laminates of any of these. The core wrap may be formed by a nonwoven web, such as a card nonwoven, spunbond nonwoven ("S"), or meltblown nonwoven ("M"), and any laminates thereof. For example, spunmelted polypropylene nonwoven fabrics are preferred, specifically those having the SMS, SMMS, or SSMMS structure of the laminate web and those having a basis weight in the range of about 5 gsm to 15 gsm. Suitable materials include, for example, U.S. Patent No. 7,744,576, U.S. Patent Application Publication Nos. 2011/0268732 (A1), 2011/0319848 (A1), and 2011/0250413 (A1). Is disclosed. Nonwoven materials obtained from synthetic fibers such as PE, PET, and especially PP may be used.

  The core wrap comprises a first substrate 16 that forms the upper side 288 of the core and a second substrate 16 'that essentially forms the lower side of the core, as shown in the cross-sectional view of FIG. Also good. Alternatively, making a core wrap from a single substrate, or using a backsheet or topsheet as a substrate to form the core wrap directly, partially or completely is also known in the art. Are known. When two substrates are used, the core wrap may have a C wrap along each longitudinal side edge 284, 286 of the core. Core wrap is not considered an absorbent material for purposes of calculating the percentage of SAP in the absorbent core. An example of a core wrap structure is further described in detail in WO 2014/093310.

  The absorbent core may comprise one or more layers of glue to help secure the absorbent material. The absorbent core 28 may comprise a layer of at least one auxiliary glue 71, 72 applied on the upper and / or lower inner surface of the core wrap. The auxiliary glue is applied directly onto the substrate to which the absorbent material is subsequently applied, and thus may at least partially fix the absorbent material on the substrate. The auxiliary glue may also at least partially form the core wrap joint 27 of the channel forming area 26. Auxiliary adhesives can also be useful to improve the adhesion of the thermoplastic material to the substrate when a fibrous thermoplastic material is present. The auxiliary adhesive can be applied by any adhesive applicator known in the art, particularly a bead nozzle, slot nozzle, or spray nozzle. For example, the auxiliary adhesive may be applied using a slot coating process as a pattern that includes a plurality of spaced slots that may each extend longitudinally. The slots may have a width of, for example, 0.5 mm to 3 mm and / or have a lateral spacing between the slots of 0.5 mm to 4 mm.

  The absorbent core 28 may also include a fibrous thermoplastic adhesive material (not shown), also known as a microfiber glue, to help further secure the absorbent material 60 within the core wrap. Fibrous thermoplastic adhesive material is typically applied by spraying on an absorbent material that has been discontinuously deposited on the substrate during the core making process, and as shown above. Lands and coupling areas are formed. The fibrous thermoplastic adhesive material contacts the absorbent material and the substrate layer in the absorbent material absent bonding area. This imparts an essentially three-dimensional network structure to the fibrous layer of thermoplastic adhesive material, which is itself a relatively thin two-dimensional structure as compared to the length and width dimensions. . Thereby, the fibrous thermoplastic adhesive material can be provided with a cavity covering the absorbent material, thereby fixing the absorbent material. A double layer core can be constructed in this way, with the land area of one layer corresponding to the non-material binding area of the other layer and vice versa, resulting in a continuous double absorbent layer.

  Further details on these glues and how they can be added in the SAP printing process are further described in US Patent Publication Nos. 2006/024433 (Blessing), 2008/0312617 and 2010 / 051166A1. (Both Hundorf et al.), As well as 2014 / 027066A1. The absorbent core can advantageously provide sufficient immobilization of the absorbent material in dry and wet conditions. The absorbent core is advantageously about 70%, 60%, 50%, 40%, 30%, 20% according to the Wet Immobilization Test described in US 2010/051166 (A1). % Or less than 10% SAP loss is achieved.

Channel formation area 26
Each absorbent core further includes at least one pair of channel forming areas 26, which will be described in further detail below. Each channel forming area 26 may comprise an absorbent material absent area in which a core wrap joint 27 is present. The channel forming area is usually not visible in the article before use due to the opacity of other layers of the article, especially when the absorbent core is substantially free of cellulose fibers and is therefore only a few mm thick. There is. As shown in FIG. 3, the thickness of the core 28 when dried is exaggerated to clearly show the channel formation area 26 and the core wrap joint 27.

  The channel-forming area is at least initially not substantially swollen when the absorbent core absorbs urine or other fluid, but the absorbent material adjacent to the channel-forming area can swell considerably. The channel forming area thus forms a three-dimensional channel when the absorbent material adjacent to the channel forming area absorbs fluid and swells. As the core absorbs more liquid, the recess in the absorbent core formed by the core wrap joint 27 between the two substrates becomes deeper and becomes more apparent visually and tactilely. With a sufficiently strong core wrap joint and / or a relatively extensible substrate material, the channel may still remain unchanged until the absorbent material is fully saturated. On the other hand, in order not to unduly limit the swelling of the absorbent material when the core is substantially loaded, the core wrap joint 27 is at least partially open or closed when the core is approaching saturation. It may be designed to rupture.

  The channel forming area can be formed in various ways. Specifically, the channel forming area is an area of the core that does not substantially include the absorbent material, and the upper side of the core wrap may be joined to the lower side of the core wrap through the area. Core wrap joints 27 between the upper and lower sides of the core wrap in these areas are supplementary glues 71, 72 and / or microfiber glue (see FIG. 5) applied directly to the inner surface of at least one of the substrates. (Not shown). This is exemplarily disclosed in, for example, International Publication No. 2012/170778. However, it is also known to form the joint using other joining means such as ultrasonic joining, crimping or thermal joining. The channel forming area also may not have such a lap joint in some cases, but the resulting channel may then be less resistant to compression and the absorbent material may be worn by the article. Can fill the channel area relatively quickly. The channel forming area may also be formed by core wrap with minimal or no surrounding absorbent material absent area.

  The channel forming areas 26 are arranged symmetrically in pairs on both sides of the longitudinal axis of the article 80 and are concave toward the longitudinal axis 80 of the article. “Concave” toward the longitudinal axis means that the channel has a point or area closest to the longitudinal axis (usually in the crotch region of the article) and that the channel is toward the front and back of the article. It means that the channel diverges as a whole from this closest point or area when extended. The minimum distance or gap between a pair of areas may be, for example, at least 5 mm, or at least 10 mm, or at least 16 mm, and may be, for example, up to 40 mm.

  The channel may advantageously be curved. The curve may have a substantially constant radius of curvature along the length of the curved portion, as shown in FIG. 2, or the radius may vary as shown in FIG. 6a. . It is also not excluded that at least a portion of the channel is straight and / or may comprise a plurality of straight sections. For example, the channel formation area may be approximated by two lines that meet at a point closest to the longitudinal axis and form a flat V-shape as shown in FIG. The channel formation area may also comprise more than two areas as shown in FIG.

  Although not shown in the figures, a portion of the channel forming area may not be concave toward the longitudinal axis, for example, a portion of the channel at the distal end toward the leading edge and / or the trailing edge of the core. It is not excluded that is parallel to the longitudinal axis or even convex (converging towards the longitudinal axis). In this case, only the concave portion of the channel formation area is considered in calculating the length-to-height ratio (see below) of the channel formation area. The absorbent core may not be curved or, as disclosed in WO 2012/1707779, in addition to the curved pair, in addition to further channel forming areas, or of the article. A channel forming area that can be disposed only in the front region may be included.

  The channel forming area 26 may be substantially free of absorbent material, so that the joint 27 between the upper side 288 and the lower side 290 of the core wrap, for example, glues these two surfaces together and / or By crimping, it can easily be formed in these areas substantially free of absorbent material. “Substantially free of absorbent material” means that there can be virtually no absorbent material in these areas. Minimal amounts such as involuntary contamination with absorbent material that can occur during the fabrication process are ignored. Within the channel formation area, the core wrap upper side 288 may be attached to the lower side 290 by the core wrap joint 27 as shown in FIGS. The portion of the channel formation area that is directly adjacent to the coupling portion 27 may be substantially free of absorbent material. The channel forming area as a whole can have a width Wc including this non-absorbing material area. In this example, the width of the channel forming area 26 corresponding to the area substantially free of absorbent material may be about 8 mm, and the channel coupling portion 27 may be about 2 mm to 3 mm. The channel forming area substantially comprises an absorbent material along at least a portion of the length of the channel forming area over a width Wc that is at least 2 mm, or at least 3 mm, or at least 4 mm, for example at most 20 mm, or 16 mm or 12 mm. May not be included. The width Wc of the area substantially free of absorbent material may be substantially constant throughout its length, or may vary along the length of the channel forming area.

  The channel forming area 26 and the coupling part 27 are advantageously substantially surrounded by the absorbent material 60 when considering the plane of the core. Specifically, they may advantageously not extend to any of the edges of the absorbent material attachment area in order to reduce the risk of leakage. Usually, the minimum distance between the channel forming area and the closest edge of the core wrap may be at least 5 mm, or advantageously at least 10 mm.

  As the absorbent material 60 swells upon absorption of fluid, the core wrap joint 27 is still attached at least initially within the channel forming area 26. As the absorbent material 60 swells with the rest of the core, the core wrap forms an elongated recess along the core wrap joint 27, as shown in FIG. 3b. These channels 26 'are three-dimensional and have been found to function as a bend line that drives the bending of the diaper to fit the wearer's anatomy and thus improve the fit of the diaper. . These channels may also serve to distribute the excreted fluid along its length to the wider area of the core. These can provide a faster fluid capture rate and a more effective utilization of the core's absorption capacity. The channel can also cause deformation of the overlapping layer, such as fibrous layer 54, and can provide a corresponding water channel within the overlapping layer. The absorbent core may comprise other areas that are substantially free of absorbent material, such as the space between the absorbent material areas, but without a core wrap joint, these unbonded areas are usually Does not form a durable three-dimensional channel.

  The core wrap joint 27 may be designed to gradually open in a controlled manner when exposed to a large amount of fluid. Thus, the bond may remain substantially intact during at least the first stage because the absorbent material absorbs a corresponding amount of fluid. In the second stage, the core wrap joints 27 in the channel provide more space for the absorbent material to swell while retaining most of the channel benefits such as increased core lateral flexibility and fluid management. Can begin to open. In the third stage, corresponding to the very high saturation of the absorbent core, a larger portion of the channel coupling may be opened to provide even more space for the swelling absorbent material to expand. it can. The strength of the core wrap joint 27 in the channel is used, for example, to adhere the two faces of the core wrap, as more absorbent material will typically cause greater swelling and put more pressure on the bond It can be controlled by changing the amount and nature of the glue applied, the pressure used to make the core wrap joint, and / or the distribution of the absorbent material. The stretchability of the core wrap material is also involved.

  The core wrap coupling portion 27 may be continuous along each channel forming area 26, but may be discontinuous (intermittent), such as formed by a series of point couplings. Each channel forming area 26 is also advantageously continuous, but may consist of discrete areas separated by small gaps, so long as a generally concave profile is formed by the discrete areas. When the auxiliary glues 71, 72 are present, they may at least partly help to form the joints 27. In general, a constant pressure can be applied to the substrate in area 26 so that the auxiliary adhesive better forms a bond between the substrates. Needless to say, it is not excluded that the core wrap joint 27 is made by other known attachment means such as crimping, ultrasonic bonding, or thermal bonding, or combinations thereof, in which case the width of the channel forming area is Further reduction can be achieved. If the auxiliary glues 71, 72 are applied to the inner surface of any of the substrates 16, 16 'as a series of longitudinally oriented continuous slots, the width and frequency of these slots is advantageously It may be such that at least one slot of the auxiliary glue is present at any height of the channel in the longitudinal direction. For example, the slots may be 1 mm wide, with the distance between adjacent slots being 1 mm, and the absorbent material absent area forming the channel forming area has a width of about 8 mm. In this example, four slots of auxiliary glue will be present on average in each of the areas 26.

  In general, the core wrap joint 27 may have the same outline as the non-absorbent material area where the core wrap joint 27 is formed due to tolerances required in some manufacturing processes, but slightly less. Can be smaller.

  The channel forming area 26 is at least partially present in the crotch region 37 of each article. Specifically, the channel forming area 26 may be sufficiently elongated to extend through the entire crotch region to the front and / or back region of the article. The channel forming area 26 may thus have a length CL that is at least 25% of the length L of the article, in particular at least 33% or at least 40% of L, and at most 90% or 80% of L.

  The channel formation area 26 is further characterized herein by the ratio of channel length (CL) to channel height (CH). The channel length (CL) corresponds to the distance between the two ends of the channel forming area, including the absence of an absorbent material present area, as indicated by line 126 in FIG. . If the channel formation area has a measurable width Wc, the center of the channel formation area at both ends is used to measure the channel length.

  The straight line 126 connecting these two ends may be generally parallel to the longitudinal axis 80 ′ of the core (see FIG. 2), but one of the ends is transverse to the other end. If the directions are staggered, it is not excluded that this line has an angle with respect to the longitudinal axis. Such an angle can be, for example, up to 25 °, or up to 20 ° relative to the longitudinal axis 80 of the article or relative to the longitudinal axis 80 'of the absorbent core.

  The channel height (CH) is the maximum distance measured perpendicular to the connecting line 126 between the line connecting the two ends of the channel forming area and the rest of the channel forming area. This is shown in FIG. 4, which is an enlarged view of the relevant part of FIG. 2 where the distance CH is measured. If the channel formation area 26 has a measurable width, as shown, the channel height refers to the central portion of the channel formation area 26, which can usually be the center of the coupling 27, as shown in FIG. Is measured by

  In the series of articles of various sizes with concave channeling areas, we have a ratio CL / CH for at least two of the series of articles, in particular for at least three of the articles. It has been found that it should increase with the size of the article to provide an optimal fit. This will be further discussed in the following section.

The present invention relates to a series of absorbent articles comprising at least two different articles, in particular at least three articles, including the channel-forming area indicated above, where the CL of the article The / CH ratio increases with the size of the article. The size of the article is usually marked directly on the absorbent article, eg printed on a backsheet, and usually also marked on the package of the absorbent article to facilitate selection by the user. A “user” as used herein may be a caretaker of an infant care article or a wearer of an adult incontinence article. The series of articles is typically part of an absorbent article lineup or system that covers a range of different article sizes. A series of absorbent articles is usually the common first designation, usually Pampers® or Luvs® (both trademarks of Procter & Gamble Company) ) And other registered trademarks. A series of articles may also be marketed under the second designation, but this second designation may be the same or different for each series of articles, for example Baby-Dry ™ or It may be Cruisers ™.

  The size of the article can be tied directly to the weight of the intended user, usually as a range of weight. For example, the size of an infant care product article is a number (size 0, 1, 2,... 6), letters (XS, S, M, L, XL ...), a brief description (newborn, mini, Midi, maxi, ...), or a combination thereof. Usually, the amount of absorbent material increases with the size of the article and advantageously further with the length and width of the article. The size of the article may therefore usually increase with the weight of the wearer, but the size of the article may additionally or alternatively be linked to the wearer's age or need for urine absorption.

  Since user needs may vary from region to region, the same size notation may be used for articles with different weight ranges by manufacturer. For example, for baby care articles, the following table directs baby diapers sold under the Pampers (R) Baby-Dry (TM) notation to various regions at the time of filing: Various size numbers are given in the weight range (in kg).

  Articles can be offered to users for sale in a variety of packaging, from individually packaged products to oversized cardboard boxes containing over 100 articles.

  The outline of the absorbent core with channel forming areas with different CL / CH ratios is schematically represented in FIGS. 5a, 5b, 5c and FIGS. 6a, 6b, 6c. These cores may be used in articles having various sizes, for example to form a series of articles according to the present invention, with the size of the absorbent article increasing from left to right. To more clearly show that the ratio CL / CH increases from left to right, these cores are represented by the same length and width, however, the cores for smaller sized articles are: It is expected to be generally smaller in the transverse and longitudinal dimensions. The ratio CL / CH (CL1 / CH1) of the core 285a shown on the left is smaller than the ratio (CL2 / CH2) of the core 285b shown in the center, and the ratio of the core 285b is itself the core 285c arranged on the right hand side. The ratio (CL3 / CH3) is smaller. In other words, since all are considered equivalent, the curve formed by the channeling area becomes flatter as the size of the article increases.

  FIGS. 6a, 6b, 6c similarly show various types of curves in the channel forming area, where the core wrap joint of the core is large towards the back side edge or the front side edge of the core. Has a radius of curvature. This can be particularly useful to align or bring the point of the curve with the maximum channel height to the core crotch point C '. The overall relationship of the ratio CL / CH is preserved in this example (CL′1 / CH′1 <CL′2 / CH′2 <CL3 ′ / CH3 ′), so that the series of products according to the invention is Can be provided by using these cores from left to right in increasing size absorbent products. The same is of course true for the cores shown in FIGS.

  The channel forming area is provided with bend lines that help improve the fit and comfort of the article. Ideally, these bend lines are the area that connects the torso and the wearer's thigh (the so-called crotch line), including the high mobility zone (towards the thigh) and the low mobility zone (towards the torso). In particular, it should follow the natural curvature of the body. This curvature varies with infant age and weight or adult body mass index. By adjusting the length and curvature of the channel, it is possible to match the intended crease of the absorbent core to the contour of the infant's leg around the wearer's crotch region. While not wishing to be bound by theory, we have found that the growth rate of the infant (leg circumference) is larger than that of older infants in infants under 9 months. The growth rate for each diaper size is about 14% to 16% at a young age (up to 9 kg infants), compared with 6% to 10% for older infants. Estimated.

In addition, the channel extends from the crotch region of the absorbent article to the front and / or back region, beyond the transition region between the low and high mobility areas of the wearer's crotch line. When reaching, improved bending can be achieved. Leg Hoop (defined by the oval circumference around the leg following the crotch line) and Rise (defined as the distance from the infant's umbilicus to the equivalent height point on the back) Are also likely to increase at a faster rate in smaller infants than in larger infants. This relationship is shown as a chart in FIG. It may also be advantageous for the channel length to increase analogously to the infant's bulge. Although not wishing to be bound to these experimental figures in a first order approximation, CL = −0.36M ² + 17.5M + 62 (a formula expressing advantageous channel length as a function of infant weight. mm) has been found by the inventors, where M is the weight of the infant in kilograms. The ratio CL / CH should also increase as a function of leg rings and bulges, but it is more difficult to accurately approximate this increase as a function of body weight. Also, local consumer habits and practices can in some cases affect the ideal perception of fit applications.

  The following table is a numerical example of the dimensions of the channel forming area (CL = channel length, CH = channel height) and how they can vary between different sizes of absorbent article lineup It shows. The article is a baby diaper. The size / weight range relationship of the articles is as follows: size 2-6 Pampers® Baby-Dry® and size 1 Pampers® New-Born at the time of filing in Western Europe. Is being used against.

  The% increase value indicates the increase in CL / CH ratio from one size to the next. In this example, a series of articles according to the invention are formed by sizes 1, 2, 3 (or 4), 5 and 6. This example also reduces the cost and complexity associated with having multiple designs, especially when the infant weight range in these article sizes has significant overlap, or the difference from the ideal channel dimensions. When not justified, the same channel design across multiple article sizes (size 4 and size 5) being offered may be acceptable. As is known in the art, additional product sizes, particularly size 4+ or size 5+ or intermediate sizes such as for neonates (size 0 or “N”) may be present in the lineup. The lineup of articles is, for example, a given first notation, which can be typically a trademark, for example Pampers®, and one or more second notations, for example Baby-Dry®. ), New-Born, Active-Fit (R) or Swaddlers (R). The relationship between weight range and article size shown in the table above may vary from manufacturer to manufacturer, especially for other product lineups or geography or time.

  The amount of absorbent material, particularly superabsorbent polymer particles, present in the article usually increases with the size of the article. The amount of AGM will usually be changed by the manufacturer depending on the different diaper changing habits in the geography considered, the absorbency and cost of the SAP used. As a purely implicit example, the following amounts of commercially available SAP can be used in the core described above.

Test Procedures Unless otherwise indicated, the values given herein were measured according to the methods set forth herein below. Unless otherwise indicated, all measurements are performed at 21 ° C. ± 2 ° C. and 50% ± 20% RH. Unless otherwise specified, all samples should be allowed to equilibrate at these conditions for at least 24 hours before performing this test. Unless otherwise specified, all measurements should be replicated on at least 4 samples and represent the average value obtained.

Centrifugal holding capacity (CRC)
CRC measures the liquid absorbed by superabsorbent polymer particles that swell freely in excess liquid. CRC is measured according to the EDANA method WSP 241.2-05.

Dry Absorbent Core Caliper Test This test can be used to measure the absorbent core caliper (before use, ie without fluid filling) in a standardized fashion. This test is described in detail in WO 2014/093311, which is incorporated herein by reference.

Absorbent Article Caliper Test The absorbent article caliper test can be performed as for the dry absorbent core caliper test, with the difference that the caliper of the final absorbent article is measured instead of the core caliper. Further details regarding this test can also be found in WO2014 / 093311.

Overall As used herein, the terms “comprise” and “comprising” are in an open-ended format. Each identifies the presence of an element (e.g., a component) described after the term, but other elements, e.g., elements well known in the art or disclosed herein. It does not exclude the presence of processes and components. These terms based on the verb “comprise” have the narrower term “consisting essentially of” to exclude any element, step, or ingredient not mentioned, which does not substantially affect the way the element performs its function, and It should be read as including the term “consisting of” which excludes any element, step, or ingredient not explicitly stated. None of the preferred or exemplary embodiments described below limit the scope of the claims, unless specifically indicated to limit the scope of the claims. The words “generally”, “usually”, “preferably”, “advantageously”, “in detail” and the like, unless specifically indicated to limit the scope of the claims. It modifies features that are not intended to limit the scope of the claims. Any feature or component described herein in connection with an embodiment may be combined with another feature or component of another embodiment unless otherwise indicated.

  Unless otherwise indicated, the legends and claims are those before use (ie, dry and free of liquids) and at least 24 hours at 21 ° C. ± 2 ° C. and relative humidity (RH) ) Refers to absorbent articles, absorbent cores or components thereof adjusted at 50 ± 20%.

  The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise indicated, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” shall mean “about 40 mm”.

Claims (15)

A series of at least two, preferably at least three, absorbent articles of various sizes, comprising a wearer facing side, a garment facing side, and an absorbent core (28), said absorbent core (28 ) Comprises an absorbent material (60) between the wearer facing side and the garment facing side,
Each absorbent article conceptually has a longitudinal axis (80), a front region (36), a rear region (38), and an intermediate crotch region (37), each region having the longitudinal axis. Having a length of one third of the length of the article as measured along
The absorbent core includes a pair of channel forming areas (26) that are at least partially present in the crotch region of the article, the channel forming areas being symmetrically opposite the longitudinal axis. Disposed and concave toward the longitudinal axis, each channel forming area having a length (CL) and a height (CH);
A series of absorbent articles, characterized in that the length-to-height ratio (CL / CH) of the channel forming area increases with the size of the article.   The series of absorbent articles of claim 1, wherein the length of the channel forming area increases with the size of the article.   A series of absorbent articles according to claim 1 or 2, wherein the length to height ratio of the series of absorbent articles ranges from 5 to 40.   4. A series of absorbent articles according to any one of the preceding claims, wherein the ratio of length to height increases by at least 10% between two consecutive sizes of the series of absorbent articles.   8. For each absorbent article in the series of absorbent articles, the channel-forming area has a length (CL) that is between 25% and 90% of the length (L) of the article. A series of absorbent articles as described in any one of 1-4.   A series of absorbents according to any one of the preceding claims, wherein the amount of absorbent material in each absorbent core, in particular the amount of superabsorbent polymer particles, increases with the size of the series of absorbent articles. Sex goods.   The series of absorbent articles according to any one of claims 1 to 6, wherein the absorbent core of each article of the series of absorbent articles is substantially free of cellulose fibers.   The absorbent material (60) of each absorbent core of the series of absorbent articles comprises at least 90% by weight of superabsorbent polymer particles, and in particular, the absorbent material consists entirely of superabsorbent polymer particles. A series of absorbent articles as described in any one of claim | item 1 -7.   The absorbent material (60) of each article is encapsulated in a core wrap (16, 16 '), and the channel forming area extends along the core wrap joint (27) with the upper side (288) of the core wrap (290). In particular, the channel forming area includes an area substantially free of absorbent material, and the area substantially free of absorbent material is surrounded by the absorbent material. The series of absorbent articles according to any one of claims 1 to 8, wherein the core wrap joint (27) is formed through an area substantially free of the absorbent material.   The series of absorbent articles according to claim 9, wherein the core wrap joint is formed by at least one of gluing, crimping, and / or ultrasonic bonding.   The absorbent material is enclosed in a core wrap, and is a thermoplastic adhesive material that fixes at least a portion of the absorbent material in the core wrap, in particular, an auxiliary glue on the upper and / or lower inner side of the core wrap. 11. A series of absorbent articles according to any one of the preceding claims, further comprising an agent (71, 72) and / or a reticulated microfiber paste applied on the absorbent material.   A lineup of articles comprising a series of absorbent articles according to any one of claims 1-11.   13. The baby care diaper lineup of claim 12, wherein the lineup includes at least five different items having sizes sized according to the weight of the baby. 14. The lineup according to claim 13, wherein the size of the article of the lineup is
A first size corresponding to an infant weight range including a boundary of 4 kg,
-A second size corresponding to an infant weight range including a boundary of 5 kg;
-A third size corresponding to an infant weight range including a border of 8 kg,
A fourth size corresponding to an infant weight range where the boundary includes 12 kg;
-A fifth size corresponding to an infant weight range including a border of 14 kg;
-A lineup selected from the group consisting of a sixth size corresponding to an infant weight range including a border of 17 kg. A method of making a series of absorbent articles according to any one of claims 1-14,
Making at least two different absorbent cores, preferably at least three different absorbent cores, each of said absorbent cores having a channel-forming area as indicated in claim 1 and at least 2 Steps having two different length-to-height ratios;
Assembling the absorbent core in various sized absorbent articles having a length to height ratio that increases with the size of the article.

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